Astronomers have discovered the embryo of an undeveloped gas giant

An international team of astronomers has announced the discovery of a previously unknown exoplanet. It represents a mini-Neptune.

Mini-Neptune as imagined by an artist. Source: ESA

The discovery was made during the analysis of photometric data collected by the TESS telescope. It managed to detect periodic changes in the brightness of the star TOI-2018. It is a metal-poor orange dwarf located at a distance of 91 light-years from Earth. Further observations carried out using ground-based observatories confirmed that TOI-2018 has a companion and provided an opportunity to determine its key characteristics.

The found exoplanet, TOI-2018 b, has a radius 2.27 times that of Earth and a mass 9.2 times that of Earth. It is unlikely to be a habitable place. The exoplanet completes one orbit around its star in just 7.44 days, and its average surface temperature is 380°C.

According to researchers, TOI-2018 b is considered a mini-Neptune. This means it has a solid core surrounded by a hydrogen-helium envelope or a mixture of ice and rocky material.

Researchers note that the physical characteristics of TOI-2018 b are close to the threshold at which rapid accretion of material occurs, leading to the formation of a full-fledged gas giant. It is quite possible that this world represents a planetary core that never developed into a large exoplanet.

Available data also suggest the presence of another exoplanet in this system. It is approximately 50% larger than our planet, with a mass of 3.6 times that of Earth. To confirmation the existence of this object additional observations are required.

Previously, we reported on how the James Webb Space Telescope could assist astronomers in the search for life in other stellar systems.